Gun for fastener projectile



April 5, 1955 c. BossoNG GUN FOR FASTENER PROJECTILE Filed D60. 11, 1951 3 Sheets-Sheet INVENTOR.- wm Basso/v6) wlllllllllll II-u-l ,April 5, 1955 c. BossoNG GUN FOR FASTENER PROJECTILE 3 Sheets-Sheet 2 Filed Dec. 1l, 1951 WAFALIIISIIL aww INVENTOR.' CARL BOSSONQ;

Illilulvllll April 5, 1955 c. BossoNG 2,705,323

GUN FOR FASTENER PROJECTILE 7L d INVENToRf m P l0 CHE/ Bossofv,

United States Patent O GUN FOR FASTENER PROJECTILE Carl Bossong, Dusseldorf, Germany, assignor to Bossong- Werk G. m. b. H., Lintorf, Germany, a corporation of Germany Application December 11, 1951, Serial No. 261,095

4 Claims. (Cl. 1-44.5)

The invention relates to a gun for impelling fastener projectiles, for use in imbedding bolts or studs or other fastening means into a solid mass such as concrete walls or steel plates or wood.

Desirable features of guns of this type include proper control of firing and safety of operation, and these features generally are found in guns of this type now in use. However, present guns are deficient therein that the reloading after firing is cumbersome and time consuming and requires considerable skill on the part of the operator. Furthermore, present guns in many cases are too heavy; and also they do not hold securely the projectile prior to firing, so that they are not always dependable; and nally do not reliably provide for automatic ejection of the empty cartridge.

It is therefore among the principal objects of the instant invention to provide a light weight gun of the type referred to that can easily and quickly be reloaded, requires but little skill for its operation, will automatically eject the empty cartridge during reloading operation, will securely reassemble the gun following reloading, and will hold the projectile securely in place prior to firing yet release it instantly upon cartridge explosion.

With the above and other objects of the invention in view, the invention consists in the novel construction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, one embodiment of the same being illustrated in the accompanying drawings and described in the specification.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:

Fig. l is a vertical sectional view, partly in elevation, of a gun in accordance with the invention;

l' Flg. 2 1s a vertical cross-sectional view taken on lme 2-2 of Fig. 1;

Fig. 3 is a fragmentary horizontal sectional View, taken on line 3-3 of Fig. 2, illustrating the cartridge ejection mechanism;

Fig. 4 is a fragmentary plan view, of the mechanism r shown in Fig. 3, and taken on line 4-4 of Fig. 3;

Fig. 5 is a fragmentary partial cross-sectional View of the mechanism shown in Figs. 3 and 4, and taken on line 5--5 of Fig. 3;

Fig. 6 is a fragmentary cross-sectional view, similar to Fig. 5, but taken on line 6-6 of Fig. 3;

Fig. 7 is a sectional view, similar to Fig. 1, but showing only a fragment, and illustrating the extended position of the gun in which the two principal parts are moved a art;

pFig. 8 is a vertical cross-sectional view, taken on line 8-8 of Fig. 7, and showing the forward principal parts not only in extended position but also following angular displacement of one part relative to the other;

Fig. 9 is a fragmentary horizontal sectional view, similar to Fig. 3 but showing the barrel that is connected to the forward principal parts in the extended position with the cartridge ejector mechanism position following cartridge ejection;

Fig. l0 is a fragmentary horizontal sectional view, similar to Fig. 9, but showing the ejector mechanism pushed back into retracted position, and a refill cartridge in place;

Fig. 1l is a vertical cross-sectional view, similar to Fig. 2, but taken on line 11-11 of Fig. 1 and illustrat- 2,705,323 Patented Apr. 5, 1955 ICC ing the locking mechanism for parts firmly together;

Fig. 12 is a vertical sectional view, similar to Fig. 1, but showing the forward principal part, and the barrel, pushed inwardly to enable the tiring pin to strike against the cartridge upon trigger release; and

Fig. 13 is a perspective view of the ejector part of the cartridge ejector mechanism.

In carrying the invention into effect .in one of the embodiments which has been selected for illustration in the accompanying drawings and for description in this specification, and referring now particularly to Fig. l, there is provided a gun for impelling fastener projectiles and which comprises a movable front sleeve generally indicated at 16, and a fixed rear sleeve, generally designated 17. The sleeves 16 and 17 normally are positioned in a rst position co-axially, as shown in Figs. 1 and 12.

Each of the sleeves 16 and 17 is provided with a downwardly extending projection, the front sleeve having the projection 18 and the rear sleeve 17 the projection 19. A bore is formed in each of the projections 18 and 19, the projection 18 having a bore 21 and the projection 19 having a bore 22. The bores 21 and 22 are co-axially aligned, and a hinge pin 23 is journalled in said aligned bores 21 and 22.

The hinge pin 23 is secured to the front sleeve 16, for instance by means of a cross pin 24. On the other hand, the hinge pin 23 is not secured to the rear sleeve 17, but instead is slidable axially in the bore 22 between a normal position shown in Figs. l and 12 and respectively an extended position shown in Fig. 7, and in that extended position furthermore is revoluble at least for a fraction of a full term about its axis, as shown in holding the two principal Fig. 8.

During the shifting and the turning movement of the hinge pin 23 described in the foregoing, the hinge pin takes along on these movements, and guides the movable front sleeve 16, for rst moving it away from the fixed rear sleeve 17 and for subsequently displacing it angularly relative thereto. Means are provided for guiding the hinge pin 23 in its movements, and for limiting the distance of shifting and the angular turning, and these means for instance comprise a cross-pin 26 that is secured at right angle to the hinge pin 22 (Figs. l and 7) and which slides in a channel 27 that is formed in the projection 18 of the rear sleeve 17. The said channel 27 is L-shaped, and includes a long arm 28 and a short arm 29 at right angle thereto. The cross-pin 26 can be shifted in the long arm 2S of the channel 27 between the end portions thereof, for a distance a (Fig. 1) which corresponds to and equals the distance b for which the movable front sleeve 16 may be shifted away from the fixed rear sleeve 17 (Fig. 7). When the crosspin 26 reaches the forward end of the arm 28 of the channel 27, it can be turned about the axis of the hinge pin 23, together with the said hinge pin 23, and be guided in the short arm 29 of the channel 27 for turning the hinge pin 23 and thereby angularly displacing the front sleeve 16 relative to the rear sleeve 17.

The rear sleeve 17 carries a handle section 31 which is secured to the rear surface of the sleeve 17, for instance by screws (not shown). An annular member 32 (Fig. l) encircles the front part of the handle section 31 and is rotatable in opposite directions D and E (Fig. 11). An extension 33 is formed on said annular member 32 and has a recess or opening 34. The rear portion of the hinge pin 23 integrally has a part 36 of reduced size adjacent a terminal ange 37, and the portion 36 of reduced size is arranged to engage the recess 34 of the extension 33. In the normal position of the hinge pin 23 (Fig. l) the part 36 thereof lies in the path of the recess 34, and is engageable thereby, to lock the hinge pin 23 and thereby the sleeve 16 in normal position.

On the interior of the front sleeve 16 there is secured a bearing ring 38, and in this bearing ring 38 there is disposed a barrel 39. The barrel 39 extends with its rear portion to the interior of a sleeve or bushing 41 that is secured in the rear sleeve 17 and terminates ush therewith frontwardly, in abutment with the bearing ring 38, when tion (Fig. l).

the sleeves 16 and 17 are in their normal abutting posi- The bushing 41 is provided with a rear portion 43 of reduced diameter. The interior diameter of the front portion of the bushing 41 is equal to the interior diameter of the bearing ring 38. When the sleeves 16 and 17 are in normal abutting position (Figs. l and l2), the barrel 39 extends into the frontward portion of the bushing 41; in the extended position of the sleeves 16 and 17 (Figs. 7, 9 and l0), on the other hand, the barrel 39 'is only carried in the bearing ring 38 but is spaced from the bushing 4l for a distance c (Fig. 7).

The barrel 39 is reciprocably slidable horizontally in the bearing ring 38 therefore also against the front sleeve 16 and, in the normal position of the sleeves 16 and 17, the barrel 39 is slidable also in the frontward part of the bushing 41, between a forward station shown in Fig. l and a firing station shown in Fig. 12. The barrel 39 has a groove 44 into which there extends from the .front sleeve 16 a pin or set screw 46 which operates to limit the reciprocation movement of the barrel 39 against the front o sleeve 16, and normally in the forward station of the barrel 39, the rearward wall of the groove 44 abuts against the set screw 46, as best shown in Fig. l. A coiled pressure spring 47 is disposed in an annular cut-out 48 of the bearing ring 38 and abuts with one end against the rear side of the cut-out 48, and presses with the forward end against a Harige ring 49 that is secured to the exterior of the barrel 39. The spring 47 thus biases the barrel 39 t0 be in forward position, shown in Fig. l.

In the front end of the barrel 39, there are provided recesses 51 for the placement therein of rings (not shown), the purpose of which will be explained later on herein. A muffler 52 is removably secured to the front end of the barrel 39 and is placed, during the use of the gun, against the material to receive the projectile, and the muer 52 serves as a splinter protector as well as a noise abater. The muffler 52 is provided in its front face with a plurality of equally distributed rubber plugs 53. As best shown in Fig. 1, the muffler 52 is detachable from the barrel 39, and is held thereon by means of a spring 54 that is inserted removably in opposite annular grooves formed in the outer surface of the barrel 39 and in the inner surface of the mufller 52; the muffler 52 abuts with its rearward end against a shoulder 56 that is formed on the barrel 39, to restrain rearward movement of the muffler 52 on the barrel 39, and to determine the proper position of the muier for placement of the spring ring 54.

The barrel 39 has a central bore 57 which extends throughout the length of the barrel and through which there is inserted and discharged the projectile, for instance the fastener 58. The projectile 58 is inserted into the bore 57 through the front end 59 of said bore 57 and may be pushed, for instance by means of a pushing rod (not shown) to the projectile-holding location 61 disposed near the rearward terminal of the bore 57. Releasable holding means, generally indicated at 62, are provided at the location 61 for temporarily holding, though instantly releasing upon tiring, the projectile 58.

The projectile-holding means 62 comprises a series of arcuate clamp members 63, and each member' 63 is movable radially of the bore 57 in a radial groove 64 of the barrel 39, and each clamp member 63 is urged towards the bore 57 by means of a spring 66 held in each groove 64 by a threaded cover 67. By this means, the clamp elements 63 frictionally engage the rear end of the projectile 58 in the location 61, but the friction developing between the clamp 63 and the projectile 58 is of such magnitude, owing to the calibrated force exerted by the springs 66, that upon firing the projectile 58 will instantly be released for forward propulsion.

A cartridge holder 68 is threaded into the rear annular threaded portion of the barrel 39, and is coaxial therewith, and has a central bore 69 that is aligned with the bore 57. Said bore 69 is dmensioned to accommodate the body of a cartridge 71, and is widened at the rear to accommodate the llange 72 of the cartridge 71. The cartridge holder 68 has the same outer dimension as the barrel 39 and is disposed therewith, in the normal position of the sleeves 16 and 17 (Fig. l), in the forward portion of the bushing 41. The cartridge holder 68 is reciprocably movable together with the barrel 39, between the stations shown in Figs. 1 and l2, respectively, and is also movable with the barrel 39 to the extended position vthereof shown in Fig. 7.

To the rear of the cartridge holder 68 there is disposed in the sleeve 41 a guide member 73, that has a bore 74 adapted for guiding the ring pin 76. Although the guide member 73 is coaxial with the barrel 39 and the cartridge holder 68, the bore 74 is offset against the bores 57 and 69 for a distance designed to let the tiring pin 76 strike against the outer portion of the cartridge flange 72.

The firing pin 76 extends rearwardly in a bore 79 through the handle section 31 and terminates within an opening 77 of the handle section 31 that accommodates the fingers of the operator when he grips the grip 78 of the handle section 31. The firing pin 76 is reciprocably slidable in the bore 79, and said bore 79 is axially aligned with the bore 74 of the guide member 73. The firing pin 76 is loaded by a spring 81 that exerts pressure between the front surface 82 of the handle section 31 and a flange 83 secured to the tiring pin 76, thereby urging the ring pin frontwardly. A cocking member 84 is connected to the rearward end of the tiring pin 76 for grasping by a nger or fingers of the operator to retract the tiring pin into the cocked position shown in Fig. 1.

A firing pin holding and release mechanism, generally designated 85, is provided in the handle section 31. The mechanism 85 comprises a spring-pressed latch 86 that is operable to protrude into the bore 79 engaging a frontward facing surface 87 of the tiring pin 76, thereby restraining forward movement thereof. A trigger 88 is pivoted at 89 to the handle section 31; the trigger 88 has one arm 90 in engagement with the latch 86. The latch 86 and arm 90 are biased by a spring 91 to depress the latch 86 downwardly for engaging the surface 87. The latch 86 has a second arm 95 extending rearwardly and may be depressed manually for latch release. Pressure exerted against the rear arm of the trigger 88 will raise the latch 86, against the force of the spring 91, thereby releasing the engagement between the latch 86 and the surface 87, permitting' forward movement of the firing pin 76 under the impulse of the spring 81.

A cartridge ejection mechanism is provided, generally indicated at 92, and illustrated in Figs. 2-6, 9, 12 and 13. The ejection mechanism 92 comprises an ejector 93 illustrated in perspective in Fig. 13. The ejector 93 has a straight section 94 that includes an arcuate outer surface the radius of which, as best shown in Fig. 6, is the same as the radius of the barrel 39 and which forms at one portion of the side of the barrel 39 a cylindrical segment, substantially completing at that side the full circle of the barrel 39. The straight section 94 has a lower surface 96 (Fig. 6) that is in sliding contact with a segmental surface 97 of the barrel 39 at that side. The straight section 94 furthermore is provided with a central elongated slot 98 extending throughout the major portion of the length of the ejector 93, and has in the arcuate surface a transverse groove forming two groove portions 99. A pawl 101 is provided opposite the ejector 93 and is reciprocably slidable in a radial passage 102 that is formed in the xed sleeve 17 and extends through the frontward portion of the bushing 41. The pawl 101 is biased by a spring 103 that urges the pawl 101 centerward. The pawl 101, as best shown in Fig. 5, has a central extension 104 and two shoulders 106 set back from. and laterally of, said extension 104, and the shoulders 106 are adapted to engage the two groove portions 99 (Fig. 3) while the extension 104 is adapted to project into the slot 98 of the ejector 93. 1n order to limit the centerward movement of the pawl 101 (Figs. 9 and l0), there is provided a nose 107 that is arranged to engage a surface 108 of the bushing 41.

To the rear of the straight section 94, the ejector is provided with a vertical arm 109 (Figs. 2, 3, 13) that has a lowermost edge 11.1. The arm 109 is received in a recess 112 (Fig. 9) of the cartridge holder 68, and the edge 111 is placed in advance of the llange 72 (Fig. l) of the cartridge 71 when the latter is emplaced in the holder 68 (Figs. 3-10). The edge 111 is so shaped as to conform to the flange 72 for engagement thereof.

Upon forward movement of the barrel 39 relative to the sleeve 17 the ejector 93 will be arrested by the pawl 101 until a cam surface 114 on the barrel 39 engages the pawl 101 to elevate it out of the grooves 99-99 on the ejector 93, and with continued forward movement of the barrel 39 a pin 113 will strike the forward end of the groove 98 to retract also the ejector forward of the sleeve 17 to the position shown in Fig. 9.

When the front sleeve 16 with the barrel 39 is moved forwardly, that is, to the left from its position as shown in Figures l and 3 from sleeve 17, to its position as shown in Figure 9, the ejector 93 will be restrained from moving with the sleeve 16, and the barrel 39 due to the engagement of the shoulders 106--106 of the pawl 101 with grooves 99-99 of the ejector, as the barrel 39 is moved forward, will result in removing the cartridge from its holder 68 due to the engagement of edge 111 on the ejector with the rim 72 of the cartridge.

The pin 113 is secured to the barrel 39 and extends into the slot 98 of the ejector 93; the cam surface 114 is formed on a tongue 116 of the barrel 39, and the tongue 116 also extends into the slot 98; all as shown in Fig. 3. When, during the continued forward movement of the front sleeve 16, the cam 114 engages the extension 104 of the pawl 101, the pawl 101 will be pressed outwardly thereby so that the shoulders 106-106 will release the groove portions 99--99, releasing the latching engagement between the pawl 101 of the rear sleeve 17 and the ejector 93 of the barrel 39; further forward movement of the front sleeve 16, will bring into engagement the pin 113 with the forward end of the slot 98 of the ejector 93, thereby causing the barrel 39 to take along in the final stage of its forward movement the ejector 93, terminating in the position shown in Figure 9. This tied movement of the sleeve 16, the barrel 39, and the ejector 93 comes to a halt (Fig. 9) when the front sleeve 16 has reached the extended position as controlled by the hinge pin 23. The cartridge 71 will drop out of the interior of the gun.

In the position shown in Fig. 9, the ejector 93 is entirely removed from the pawl 101, and can therefore manually be reciprocated on the barrel 39. Before insertion of a new cartridge, the arm 109 will therefore be pushed back manually to its original position on the barrel 39 (Fig. 10), and thereupon the cartridge emplaced. The arm 109 is provided with an outwardly forwardly slanting surface 118 which is designed to engage the extension 104 of the pawl 101, so that during the return movement of the front sleeve 16 to the normal position, the pawl 101 will be pressed outwardly by the surface 118, for subsequently gliding on the cam 114 and nally again engaging with its shoulders 106-106 the groove portions 99-99 of the ejector 93.

The operation of the above described embodiment of the invention is as follows:

After a projectile has been fired, in order to prepare the implement for the next driving of a fastener, the operator will grasp the cocking member 84 and pull it rearwardly until the latch 86 engages the surface 87, thereby cooking the tiring pin 76 for the next shot.

Subsequently, the operator will turn the annular member 32 (Fig. 11), in direction D until the recess 34 of the extension 33 thereof releases the part 36 of reduced size that as formed on the hinge pin 23, as shown in broken lines in Fig. 11. This unlocks the connection between the front and rear sleeves 16 and 17, and the front sleeve 16 may thereafter be pulled forwardly from its normal position of abutment with the fixed rear sleeve Thereafter, the operator will manually pull forwardly the front sleeve 16, from the normal assembled position shown in Fig. 1 to the extended position shown in Fig. 7, and the sleeve 16 is guided throughout by the hinge pin 23 the axial distance of shifting of which is limited by the cross pin 26.

During forward movement of the sleeve 16 and therewith of the barrel 39, relative to the sleeve 17, the ejector 93 will be arrested by the pawl 101, and thus for a time will remain at rest while the barrel 39 is moved forward. By this arresting, the vertical arm 109 of the ejector 93 will eject the cartridge 71. The ejector 93 will remain so arrested until the cam surface 114 on the barrel 39, during the continued forward movement of the barrel 39, engages the pawl 101 to elevate the shoulders 106-106 thereof out of the grooves 99--99 of the ejector 93 and, with the continued forward movement of the barrel 39, the pin 113 of the barrel 39 strikes the forward end of the groove 98 to move the ejector 93 forwardly relative to the sleeve 17. When the front sleeve 16 has reachmed the extended position shown in Fig. 7, the barrel 39 and the cartridge holder 68 will have been removed entirely olf the interior of the rear fixed sleeve 17, and the ejector 93 will be in position shown in Fig. 9. Thereupon, the operator will turn the front sleeve 16 about the axis of the hinge pin 23 to the loading position shown in Fig. 8, in order to move the barrel 39 out of alignment with the bushing 41, at. an angle relative to the previous extended position. This turning movement is guided by the cross pin 26 which moves in the short arm 29 of the channel 27.

In this loading position, the operator will insert a new projectile into the bore 57 through the frontward end 59 thereof and push it rearwardly, for instance by means of a loading rod (not shown), until the projectile 58 has reached in the bore 57 the location 61 wherein it will be engaged frictionally by the clamp members 63 that are pressed by the springs 66. Then the operator will push the ejector 93 by hand forwardly into the position shown in Fig. 10 and insert a new cartridge 71.

Subsequently, the operator will turn the front sleeve 16 from the loading position (Fig. 8) into the extended position (Figs. 2 and 7) and subsequently will manually retract the sleeve 16 until it is again in the assembled position shown in Fig. l, the barrel 39 and cartridge holder 68 sliding into the front part of the bushing 41 that is secured in the rear sleeve 17. Finally the operator will turn the annular member 32, counter-clockwise to lock the hinge pin 23, by engaging the recess 34 over the portion 36 of the hinge pin 23, and therewith locking the sleeves 16 and 17.

The gun is now loaded.

When it is desired to lire a projectile, the operator will press the muffler 52 with its front end against the surface of the material which is to receive the projectile, thereby pushing the barrel 39 and cartridge holder 68, against the force of the spring 47, from the position shown in Fig. l into the position shown in Fig. 12. In this position, he will press downwardly the rear arm 95 of the trigger 88, thereby unlatching the latch 86 against the power of the spring 91, causing the spring 81 to propel the tiring pin 76 to strike the flange 72 of the cartridge 71. The ensuing explosion will propel the projectile 58 forwardly in the bore 57 and discharge the same through the front end 59 of said bore 57 and into the material, after having removed it instantly from the location 61 wherein it was resiliently and releasably held by the clamp members 63.

If a projectile is to be shot into a comparatively soft material, such as wood, a ring (not shown) may be inserted into the recesses 51 that are provided on the front end of the barrel 39; this ring will be engaged by the projectile, and penetration of the projectile into the wood thereby be limited accordingly. In order to hold the ring in the recesses 51, the front end of the barrel 39 may be magnetized, and the ring may be made of magnetizable material, for magnetic inter-attraction.

It will be apparent to those skilled in the art that the novel principles of the invention disclosed herein in connection with specific exemplications thereof will suggest various other modifications and applications of the same. It is accordingly desired that in construing the breadth of the appended claims they shall not be limited 1t'lo th e specific exemplifications of the invention described erein.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

l. In a gun, for use in driving a fastening projectile into a solid mass, in combination, two sleeves normally positioned coaxially in an assembled position of abutment and of axial alignment of bores, and movable axially relative to each other to an extended position wherein the sleeves are spaced from each other and in that position rotatable relative to each other to a loading position of spaced and angular displacement, a barrel mounted in the first of said sleeves and projecting into the second sleeve in said assembled position and, respectively, being in said extended and loading positions removed off said second sleeve, said barrel having on the interior bore for receiving a projectile and a flanged cartridge adjacent and to the rear of said projectile, biased clamping means connected to said barrel and operable for resiliently clamping said projectile, a firing mechanism connected to said second sleeve, means for limiting the movement of one sleeve relative to the other comprising a hinge pin extending between said sleeve and being secured to one of said sleeves and slidable between normal and extended extreme stations corresponding to and defining said assembled and extended positions of said sleeves and being rotatable in the extended extreme station, means intermediate said hinge pin and the other of said sleeves operable to limit movement of said hinge pin axially and to limit the turning of said hinge pin about its axis, and means journalled on said other sleeve and operable to lock said hinge pin releasably when said sleeves are in said assembled position.

2. In a gun, as claimed in claim 1, together with, means for ejecting the cartridge near said extended position, and comprising, an ejector member guided on said barrel and being slidable axially of said barrel and having an extension normally positioned in advance of the ange of said cartridge, arresting means connected to said second sleeve and operable to engage releasably the ejector member to arrest it temporarily when said barrel is moved withsaid rst sleeve from said assembled position towards said extended position, whereby the empty cartridge will be ejected during the period of engagement while said rst sleeve is moved away relative to said second sleeve, said barrel having an external cam surface for engaging said arresting meansto release the same before said barrel has reached said extended position.

3. Ina gun, as claimed in claim 1, said releasable locking means for saidvhinge pin comprising an annular member coaxially journalled on said other sleeve and being turnable thereon in opposite directions and including an extension having an opening partaking in the turning of said member, said hinge pin including a portion of reduced size spaced from an end of said hinge pin and being adapted to t into said opening and disposed in the said first position of said sleeves in the path of said opening for releasable locking engagement thereby.

4. In a gun, as claimed in claim 1, each of said two sleeves comprising a projection having a bore, said bores being in alignment in all positions of said sleeves, said hinge pin being disposed in said bores, the projection of one of said sleeves defining an elongated channel disposed radially of said bore and communicating therewith, said limiting means intermediate said hinge pin and said sleeve comprising a cross pin connected to said hinge pin and extending at right angle therefrom and being disposed n said channel, said channel having a length equal to the distance of displacement in axial direction between said sleeves in said extended position and having terminal walls dening the ends of said channel and having a branch at right angle to the longitudinal direction of said channel, said cross pin being movable in' said channel between said walls thereby limiting the axial movement of said hinge pin, and being movable in said branch 'for guiding said hinge pin during turning thereof in said extended extreme station.

References Cited in the file of this patent UNITED STATES PATENTS 1,984,117 Davis Dec. 11, 1934 2,221,157 Temple Nov. 12, 1940 2,400,878 Dunn May 28, 1946 2,501,362 Temple Mar. 21, 1950 2,518,395 Sopris Aug. 8, 1950 

